Baseline main mechanical, energetic and cross-bridges kinetic variables.

ΔL = maximum extent of shortening; Vmax = maximal unloaded shortening velocity; AF = isometric active force normalized per cross sectional area (CSA); +dF/dt = peak of positive force derivative normalized per CSA; Vrmax = maximum lengthening velocity; −dF/dt = peak of negative force derivative normalized per CSA; G = curvature of the hyperbola; Emax = non-normalized maximum power output; Effmax = maximum mechanical efficiency; m = total number of cross-bridges per mm2; π = elementary force developed per cross-bridge; kcat = myosin ATPase activity. Values are expressed as mean ± SEM. * Pversus control.